Listeriosis Risk Model for Cancer Patients Who Consume Ready-to-Eat Salad

Area of Science:

• Food safety
• Microbiology
• Risk assessment

Background:

• Listeria monocytogenes poses a higher risk to immunocompromised individuals, including cancer patients.
• Neutropenic diets often exclude fresh produce due to pathogen concerns, but risks are unquantified.
• Ready-to-eat (RTE) salads are a common food item consumed by cancer patients.

Purpose of the Study:

• To develop a data-driven risk model for listeriosis in cancer patients consuming RTE salads.
• To evaluate the impact of kitchen-scale treatments and storage on pathogen risk.
• To assess the efficacy of interventions as alternatives to produce exclusion.

Main Methods:

• Utilized Monte Carlo simulations to model invasive listeriosis risk during chemotherapy.
• Quantified risk reduction from refrigeration, surface blanching, and rinsing of salad components.
• Conducted sensitivity analysis to identify key risk-influencing parameters.

Main Results:

• Refrigeration reduced median risk by approximately 0.5 log.
• Surface blanching with greens rinsed decreased risk to 5.4 × 10^-10.
• A blanched salad of only cucumbers and tomatoes yielded the lowest risk (1.4 × 10^-13).
• FDA-recommended rinsing reduced risk by only 1 log.

Conclusions:

• Kitchen-scale pathogen reduction methods are highly effective in mitigating listeriosis risk.
• These interventions can be considered as alternatives to neutropenic diets that exclude fresh produce.
• Reducing uncertainty in dose-response parameters can enhance model accuracy for risk management.